1. Field of the Invention
Aspects of the present invention relate to a fuel cell system that includes a fuel processor, and a method of operating the fuel cell system.
2. Description of the Related Art
A fuel processor generally has a configuration in which, after reforming a hydrocarbon group fuel source, into a reformed gas suitable for use on electricity generation reaction in a fuel processor, the reformed gas is supplied to an anode of a stack of a fuel cell system, to drive the electricity generation reaction.
When a fuel is reformed in a fuel processor, the fuel undergoes a series of processes, such as, a desulphurization process, in which sulfur components in the fuel source are reduced, a reforming process, in which the fuel source is reformed to a hydrogen-rich gas, and a CO removing process, in which CO produced as a by-product in the reforming process is removed. The reformed hydrogen-rich gas (also referred to as a reformed gas) is supplied to an anode of the stack. Then, an electricity generation reaction occurs in the stack, between the reformed gas supplied to the anode, and air (oxygen) supplied to a cathode.
In order to efficiently operate a fuel cell system, it is necessary to rapidly increase an initial start-up temperature. In particular, in the reforming process and the CO removing process, if the temperature is not above a suitable level, a desired reaction result is not obtained. Thus, in order to rapidly operate the fuel cell system in a normal operation mode, it is necessary to be able to rapidly produce a reformed gas, through a rapid temperature increase at the initial start-up. The reformed gas output from the fuel processor, before a normal operation is reached, cannot be supplied to the stack, or discharged to the outside, and thus, a method of treating the reformed gas must be provided.
Therefore, a fuel cell system must be manufactured to have a structure that can be efficiently operated, in consideration of the above matters.